I have loved making the Practical Arduino RFID Access Control System, and using the unaltered code from the website, itappears to read the card without problem (see below) but when I enter the 00FFFFFFFF into the programme at Tag 1(see below) it still comes back with 'Tag not authorised'. Should I be changing some other parameters such as tagBytes[6] or tagValue[10] or perhaps change "while (bytesRead < 12)" etc. Note the writable cards/tags I am using have not been programmed and are just straight from the manufacturer. Do they perhaps need to be programmed to a certain format first?

I know this post might not be as sexy as trying to get a NFD to work with the RFID shield, but can someone at least tell this RFID novice if you actually need to programme a 'blank' card/fob straight out of the factory, or should the ID-20LA combined with the Practical Arduino sketch be able to read and recognise any 125kHz EM4001 type card regardless of the code on it?

Assuming its a standard 125Khz card, it should be able to read the UID fine straight from factory. However if it is a HID card or something like they, they can do some funky stuff to it.

I'm assuming you have already past this though:

You will need to "Read" the card first to find out the UID of the card. Each RFID Card has a unique UID. Once you have this unique UID you can then put it into the sketch as an "Approved" or "Allowed" card to unlock the door.

I'm not familiar with how the practical arduino sketch works, but I assume is has a section in it for "approved" or "allowed" cards.

Also, with regards to reading the UID of the card, I think they supply a small snipped of code you can run to see if your device is working. This may allow you to read the UID from the serial interface.

Thanks for the feedback. The sketch does show the UID it has read, but I'm wondering it it shows everything it has read or whether it is truncating things. I think I'm going to have to buy a proper card reader/burner/writer that can display exactly what it has read.

Finally got a burner, and discovered that the Test Card that was sent with it also reads as 00FFFFFFFFF via the serial monitor, even though it is clearly labelled as 0002917212 044,33628. I've even directly entered 0002917212 into the sketch to see if it might read it correctly such that it might be just the serial monitor showing the wrong casrd read, but no.

I have not changed anything else in the sketch from what I downloaded, but I am using an ID-20LA instead of the ID-12 or ID-20. I wouldn't have thought that would make a difference though? Perhaps the ID-20LA has different requirements from the ID-20??